From b51ff1721ddc2080c4f7e487f67c4f1a722bf091 Mon Sep 17 00:00:00 2001
From: wintergua <wintergua.cui@bambulab.com>
Date: Fri, 6 Sep 2024 10:07:14 +0800
Subject: [PATCH] FIX: brim should be extruded only on first layer

github: github.com/bambulab/BambuStudio/issues/4678

Change-Id: Ib00795dfba2e6d869c30ac906385f170088bbfd6
---
 src/libslic3r/GCode.cpp | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index 18052e425..5d5b94923 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -3767,16 +3767,18 @@ GCode::LayerResult GCode::process_layer(
                 for (ObjectByExtruder::Island &island : instance_to_print.object_by_extruder.islands) {
                     const auto& by_region_specific = is_anything_overridden ? island.by_region_per_copy(by_region_per_copy_cache, static_cast<unsigned int>(instance_to_print.instance_id), extruder_id, print_wipe_extrusions != 0) : island.by_region;
                     //BBS: add brim by obj by extruder
-                    if (this->m_objsWithBrim.find(instance_to_print.print_object.id()) != this->m_objsWithBrim.end() && !print_wipe_extrusions) {
-                        this->set_origin(0., 0.);
-                        m_avoid_crossing_perimeters.use_external_mp();
-                        for (const ExtrusionEntity* ee : print.m_brimMap.at(instance_to_print.print_object.id()).entities) {
-                            gcode += this->extrude_entity(*ee, "brim", m_config.support_speed.value);
+                    if (first_layer) {
+                        if (this->m_objsWithBrim.find(instance_to_print.print_object.id()) != this->m_objsWithBrim.end() && !print_wipe_extrusions) {
+                            this->set_origin(0., 0.);
+                            m_avoid_crossing_perimeters.use_external_mp();
+                            for (const ExtrusionEntity* ee : print.m_brimMap.at(instance_to_print.print_object.id()).entities) {
+                                gcode += this->extrude_entity(*ee, "brim", m_config.support_speed.get_at(cur_extruder_index()));
+                            }
+                            m_avoid_crossing_perimeters.use_external_mp(false);
+                            // Allow a straight travel move to the first object point.
+                            m_avoid_crossing_perimeters.disable_once();
+                            this->m_objsWithBrim.erase(instance_to_print.print_object.id());
                         }
-                        m_avoid_crossing_perimeters.use_external_mp(false);
-                        // Allow a straight travel move to the first object point.
-                        m_avoid_crossing_perimeters.disable_once();
-                        this->m_objsWithBrim.erase(instance_to_print.print_object.id());
                     }
                     // When starting a new object, use the external motion planner for the first travel move.
                     const Point& offset = instance_to_print.print_object.instances()[instance_to_print.instance_id].shift;